1. Field
The present invention relates to a communication-quality measuring apparatus capable of measuring communications quality regarding packet losses in a packet switching network by acquiring (capturing) packets transferred via a packet switching network and analyzing the acquired packets, and relates also to a communication-quality measuring method thereof, and a computer program.
2. Description of the Related Art
Conventionally, bidirectional communications via a packet switching network is possible. For example, voice telephony via the Internet is possible by transmitting and receiving packetized voice data or moving image data with voice via a packet communications network. Such voice telephony may be realized by a VoIP (Voiceover Internet Protocol), for example, and utilized as an IP telephone.
In voice communications such as an IP telephone, the voice data, in which voice is sampled at a certain rate, is transmitted and received, and thus, the amount of data to be transmitted and received is larger compared to the transmission and reception of text data. As IP telephones become widespread, the load on a network caused by voice communications tends to accumulate, and as a result, the frequency at which a packet is lost at the time of transferring the packet in a packet switching network is increased, thereby lowering communications quality of the IP telephone. Therefore, in order to quickly take action when communications quality has lowered, there have been proposed various technologies of measuring apparatuses or measuring methods concerning communications quality.
For example, there is proposed a measuring apparatus and a measuring method adapted so that a window size indicating an amount of packets to be dropped is changed according to an occurring interval of destroying the packets to adjust so that a processing capability is not exceeded (for example, Japanese Published Unexamined Patent Application No. 2000-41046), which can be put into practical application as a technology for effectively calculating a packet loss rate even in a measuring apparatus with inexpensive and low specifications.